What You Need to Know About Omega-3 and Omega-6 Supplements

If you have heard about omega oils and are considering taking omega-3 and omega-6 supplements, here is what you need to know to help you decide.

What are omega oils?

Omega oils are essential fatty acids. This means your body needs them for growth and development, but cannot generate them, so you have to get them from food. Dr. Frank Sacks, professor of Cardiovascular Disease Prevention at the Department of Nutrition in the Harvard School of Public Health, says we need omega-3 to control blood clotting and to build cell membranes in the brain. He adds that it has health benefits ranging from protection against heart disease and stroke to possibly protecting against cancer, inflammatory bowel disease and some autoimmune diseases. We also need omega-6 to lower bad (LDL) cholesterol levels, reduce inflammation and protect against heart disease.

Omega-6 and omega-3 balance

People are often confused about the relative merits of the omega oils. Sacks says that the idea that omega-3 fatty acids are somehow better than omega-6 is unsupported by scientific evidence; both are healthy and beneficial. He also disregards concerns about the source of omega-3 oils, saying that the alpha-linolenic acids (ALA) found in vegetable sources appear to be as beneficial as the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fatty fish.

However, the University of Maryland Medical Center (UMMC) says that the average American diet gets plenty of omega-6 from vegetable oils, such as safflower, sunflower, grape seed and soybean oils, and from poultry like chicken, turkey or duck. In contrast, it says omega-3 (found in flax seeds, walnuts, soybeans and tofu, or in oily fish like sardines, salmon, tuna and halibut and also shrimp and scallops) may be underrepresented in the diet. So even though omega-6 oils may be as beneficial as omega-3 oils, the chances are you don't need to supplement them, and an omega-3 supplement may be better after all.

Recommended servings of fish

Both Sacks and the UMMC agree with the American Heart Association (AHA) that fish oils are better when obtained from food rather than supplements. The AHA recommends eating at least two portions of fish per week. The U.S. Environmental Protection Agency recommends no more than a single 6-ounce serving per week of sport-caught fish for pregnant or nursing women and less than 2 ounces per week for young children. The U.S. Food and Drug Administration recommends that pregnant or nursing women and young children avoid fish with higher levels of mercury, such as mackerel, shark, swordfish or tilefish.

Cautions and contraindications

The UMMC advises against taking more than 3 grams of omega-3 in capsule form without medical supervision. The following cautions apply:

Ensure all fish or fish oil is sourced reputably and doesn't contain high levels of heavy metals, such as mercury or other contaminants.

People who bruise easily, have blood disorders or are taking blood-thinning medication such as warfarin, clopidogrel or aspirin need medical advice before taking fish oil supplements, which may further thin the blood.

People with diabetes or schizophrenia may be unable to convert ALA to EPA or DHA and should seek medical advice prior to supplementation. UMMC states that ALA may increase the risk of macular degeneration and prostate cancer, though further studies are needed to confirm this.